Travel to space is exorbitantly expensive. It would be beneficial to significantly reduce the costs associated with space travel.
The trip of 200 miles and twenty minutes from Earth to orbit takes 70% to 80% of the propellant needed to go to the moon and most other locations in our near universe. Over 90% of the weight of Earth to orbit (ETO) vehicles is currently propellant and each pound of the useful payload costs about $10,000 per pound to transport to orbit. Thus, any of the original vehicle that can be reused returns about $10,000 per pound for every pound reused on every reuse mission. Reusing vehicle hardware in space many times provides a significant return on the original investment. The present invention provides innovation to efficiently use the same Earth to orbit launch vehicle payload diameter for both the initial launch and later launches.
Reusable launch vehicles are starting to emerge off the drawing boards for the transportation from Earth to orbit, but little effort is dedicated to reusable vehicles for transport beyond Earth orbit. The present invention pertains to reusable vehicles used beyond Earth orbit and the propellant necessary for those vehicles beyond Earth orbit. Transferring propellant tanks is one of several methods to potentially reduce the complexity and cost of in-space transportation vehicles and their logistics support systems.
Space transportation vehicles typically have fixed payload diameter requirements. Maximizing use of the fixed payload diameter is one means to get the most value out of the costs associated with a launch.
Reusable in-space transportation vehicles are initially transported to Earth orbit as payloads on vehicles launched from the Earth surface to low Earth orbit (LEO). Once in space, they operate as in-space vehicles, traveling from Earth orbit to destinations beyond. When being transported as payload to orbit, the propellant tanks for the in-space vehicle must share the payload diameter with the vehicle itself. Accordingly, small tanks are launched into orbit with the in-space vehicles.
It would be desirable to use the same Earth to low Earth orbit launch vehicle payload diameter for both the reusable vehicle loaded with propellant and the next series of resupply propellant tanks. Larger tanks (without an in-space vehicle) could be launched in subsequent missions to use the full diameter of the Earth to orbit delivery vehicle.
A problem is the initial propellant tanks would be about one third the diameter of the later resupply tanks. However, both size tanks must fit within the same reusable vehicles in orbit.
It would be desirable to build a commercial relationship with an Earth to Orbit (ETO) vehicle transportation supplier by using their vehicles many times to maximize the effect of the reusable vehicle economies.
The payload diameters, tankage weight and the unmanned transfer process are critical to the cost effectiveness of a logistics system beyond Earth orbit. The present invention provides solutions in a commercial business environment, where excessive cost creates a barrier to further development and logistics support of operations on celestial bodies beyond Earth.